1. Field of Invention
The present invention relates to a microwave oven and a control method thereof, and more particularly, to a microwave oven capable of controlling a cooking time with the use of a humidity sensor and a control method thereof.
2. Description of the Related Art
When cooking with a microwave oven, a sensing means such as an infrared sensor or a humidity sensor may be used to control a cooking time. By way of example, where an infrared sensor is used, the infrared sensor can sense an internal temperature of a cooking chamber of the microwave oven and control the cooking time based on the sensed temperature. Where a humidity sensor is used, the humidity sensor can sense a humidity of steam discharged from the inside of the cooking chamber and control the cooking time based on the sensed humidity.
In a microwave oven employing a humidity sensor, the humidity sensor is generally constructed to sense a change in an amount of steam generated while a food is being cooked or a change in time during which the steam is generated, as a voltage value. In other words, the humidity from the steam generated during cooking by the microwave oven is sensed as a voltage value and the cooking time can be controlled according to the kind of food to be cooked, based on the sensed voltage value.
However, noise due to electromagnetic waves generated in a magnetron during a cooking operation of the microwave oven may affect the humidity sensor causing it to malfunction. Furthermore, generation of a derivation in measuring the voltage because of the inherent nature of the humidity sensor may cause a difficulty in controlling the optimal cooking time.
Additionally, where a user wishes to cook another food immediately after a food has finished cooking, the sensitivity of the humidity sensor may be deteriorated because the humidity sensor may not have cooled sufficiently. Even while a food is being cooked in the microwave oven under the condition that the steam inside the cooking chamber has not been completely discharged out and remains inside the cooking chamber, it may not be possible to accurately sense the humidity by use of the humidity sensor, thereby making it difficult to control the optimal cooking time for the concerned food.